This invention relates to consumable ribbon materials, particularly in printers and related equipment. More particularly, the invention relates to an improved core and spindle for ribbon materials used in equipment, such as printers, for producing data bearing identity documents, including cards such as identification cards, drivers licenses, credit cards and the like, and booklets such as passports and the like.
Ribbon materials, such as printing ribbons, cleaning tape, index tape, labels, topping foil, and holographic overlay tape, used in printers and related equipment for producing data bearing identity documents are known. The ribbon material is usually supplied from a supply roll, and, after use, is wound onto a take-up roll. The take-up roll typically comprises a cylindrical core or spool that is mounted on a spindle which is driven in rotation so as to wind used ribbon material onto the core as the ribbon is used. The core is intended to slide on and off of the spindle so that the core can be easily inserted onto and removed from the spindle.
A problem with existing core and spindle technology is that as the ribbon material is wound onto the core, the ribbon material compresses the core radially inward, causing the core to contract. As the core contracts, the interior surface of the core engages the exterior surface of the spindle with an increasing compression force. In effect, the core squeezes the spindle as the ribbon material is wound onto the core. When this occurs, removal of the core from the spindle is difficult if not impossible. Often times, the compression force is so great that the ribbon material must be unwound from the core, while the core is still disposed on the spindle, until the compression force is removed, at which point the core can be removed from the spindle. A similar problem can occur with supply rolls when new ribbon material is being wound onto a supply roll core disposed on a spindle.
Therefore, there is a need for improved core and spindle technology for ribbon materials that prevents the core from being squeezed onto the spindle as ribbon material is wound onto the core, thereby facilitating removal of the core from the spindle.
The invention provides improvements relating to core and spindle technology for use with ribbon materials. The invention has use in many environments in which a ribbon or sheet material is wound onto a core. In the preferred embodiment, the ribbon materials are those associated with printers and related equipment used to produce data bearing identity documents, including cards such as identification cards, drivers licenses, credit cards and the like, and booklets such as passports and the like. Examples of ribbon materials include printing ribbons, cleaning tape, index tape, labels, topping foil, and holographic overlay tape. The invention is beneficial for both ribbon take-up rolls in which used ribbon material is wound onto the core, as well as ribbon supply rolls in which new or unused ribbon material is wound onto the core.
In one aspect of the invention, a core for ribbon material is provided. The core comprises a hollow cylinder having a first open end and a second open end, an exterior surface and an interior surface, and a plurality of circumferentially spaced ribs connected to and extending inwardly from the interior surface.
In yet another aspect of the invention, a spindle for receiving a core thereon is provided. The spindle comprises a cylindrical member having a first exterior surface, and a plurality of ridge members extending outwardly from the first exterior surface. Each ridge member has sidewalls and an outer wall between the sidewalls. The outer walls of the ridge members define a second exterior surface, and the ridge members are spaced from each other so that facing sidewalls of adjacent ridge members define a channel between each adjacent ridge member.
In still another aspect of the invention, a combination of a core and spindle is provided. The core, which is to receive ribbon material thereon, includes a hollow cylinder having a first open end and a second open end, an exterior surface upon which ribbon material is to be wound, and an interior surface. In addition, a plurality of circumferentially spaced ribs are connected to and extend inwardly from the interior surface. The spindle, which is to receive the core thereon, includes a cylindrical member having a first exterior surface, and a plurality of ridge members extending outwardly from the first exterior surface. Each ridge member has sidewalls and an outer wall between the sidewalls. The outer walls of the ridge members define a second exterior surface, and the ridge members are spaced from each other so that facing sidewalls of adjacent ridge members define a channel between each adjacent ridge member. Further, the channels are sized to receive the ribs in close fitting relation, and, when the core is disposed on the spindle, a gap is provided between an inner edge of each rib and a base of each channel.
For a better understanding of the invention, its advantages and objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying description, in which there is described a preferred embodiment of the invention.